Peter Lymburner Robertson (1879–1951) was a Canadian inventor, industrialist, salesman, and philanthropist who popularized the square-socket drive for screws (often called the Robertson drive). Although a square-socket drive had been conceived decades before (having been patented in 1875 by one Allan Cummings of New York City, U.S. Patent 161,390), it had never been developed into a commercial success, and Robertson's efficient manufacturing technique using cold forming for the screw's head is what made the idea a commercial success.[1] He produced his screws (patented in Canada in 1909) in his Milton, Ontario factory starting in 1908. The brand has been sold over the years,[2] and the manufacturing for the present corporation (Robertson Inc) is done in Jiaxing, Zhejiang, China; but the Milton, Ontario, building is still a head office.[3]
Robertson also wrote a book (short title The Remedy, 1932)[4] which suggested a strategy to end the Great Depression. It discussed topics including national debts, currencies, and the gold standard.
Robertson was born in 1879 in Seneca Township, Ontario. As a salesman for a Philadelphia tool company in eastern Canadian sales territories,[5] he was demonstrating tools one day when his straight-bladed screwdriver slipped and cut his hand (a common mishap with the straight slot design). This prompted him to design a different drive for screws that would slip less, leading to his square-socket drive.
Robertson is still remembered by the school in Milton, Ontario, named after him, P.L. Robertson Public School (K-8).